This invention relates to a flexible sheet suitable to be used as a component of disposable body fluid-absorbent garments such as disposable diapers, urine absorbent pads or sanitary napkins, or of other garments such as disposable gowns conveniently used in medical fields.
FIG. 8 of the accompanying drawings is a perspective view showing a microapertured plastic sheet 110 described in Japanese Patent Application Disclosure No. 1987-57551 and claimed to afford a soft touch. The plastic sheet 110 is suitable for use as a topsheet and/or a backsheet of disposable diapers and formed on its upper surface with a plurality of cylindrical projections 120 which are, in turn, formed on their tops with microapertures 125. Such a plastic sheet 110 is described to offer a soft cloth-like touch.
In the case of the known plastic sheet, the microapertures formed on the tops of the respective cylindrical projections have their peripheral edges finely divided to present a petal-like appearance. When the plastic sheet is used, for example, as the topsheet of sanitary napkin, the petal-like peripheral edges will give the napkin wearer a soft touch as the petal-like peripheral edges rub her skin. However, an amount of menstrual discharge reaching a space defined between each pair of adjacent cylindrical projections rising on the upper surface of the plastic sheet can not easily move into the respective microapertures and may stay in the space. In other words, it is difficult for menstrual discharge to permeate the topsheet into an absorbent core as rapidly as possible.
It is an object of this invention to provide a flexible sheet that has a soft touch and at the same time to improve a permeability for body fluids than can be adapted for use as a component of body fluid-absorbent garment such as a disposable diaper or of other garments such as a disposable gowns conveniently used in medical fields.
According to this invention, there is provided a flexible sheet having upper and lower surfaces and being suitable for use as a component of disposable body fluid-absorbent garment, comprising:
the flexible sheet comprising a plastic sheet forming a part of the upper surface and a fibrous assembly bonded to a lower surface of the plastic sheet to form the remaining part of the upper surface of said flexible sheet and the entire lower surface of said flexible sheet;
the plastic sheet being formed with a plurality of projections occupying about 5xcx9c70% of a surface area of said plastic sheet each being convex upward with a height of about 0.01xcx9c0.5 mm from the upper surface and having a planar configuration circumscribed around a circle having a diameter of 0.25xcx9c5 mm, a plurality of ribbon-shaped regions extending in one direction in parallel one to another each having a thickness of about 0.001xcx9c0.05 mm and a width of about 0.03 xcx9c1 mm, a plurality of fine slits extending in the one direction each being defined between each pair of adjacent ribbon-shaped regions, a plurality of bridge-like regions each extending from a pair of edges of adjacent ribbon-shaped regions transversely opposite to each other with the fine slit therebetween edges to connect the adjacent ribbon-shaped regions and a plurality of rising regions extending upward from the upper surface of the plastic sheet and undulating in the one direction so as to form sawtooth waves;
and the fibrous assembly comprising component fibers assembled by mechanically intertwining, heat-sealing adhesively bonding them together and containing at least one of thermoplastic synthetic fiber, chemical fiber and natural fiber wherein the component fibers are partially exposed within the respective fine slits of the plastic sheet.